In internal combustion engines, valves may be used to control a flow of medium, in particular a thermostat of a coolant circuit of the internal combustion engine. Such control valves may comprise a valve housing in which an expansible material element is arranged in a valve body which is operatively connected to an energy accumulator which has an abutment element which may be positioned adjacent to a corresponding valve seat.
Control valves of this type are known, for example, as thermostats of coolant circuits. However, such control valves may also be used in another medium circuit of the internal combustion engine, for example in an oil circuit.
DE 195 47 493 C1 describes a method and a device for initial filling of a fluid circuit of an internal combustion engine with a fluid which is delivered by a fluid feed pump to the fluid circuit. Arranged in the fluid circuit is a spring-loaded stop valve which is moved at least temporarily to an open position for the initial filling, in particular for the initial filling of the oil circuit with lubricating oil. At the start of the initial filling, the stop valve is already set in the open position by a distance element. The distance element is arranged between the seat face of the valve body and the seat face of the valve housing and is in the form of an elastic flap. A venting gap via which the air is displaced from the oil passages by the oil feed pump is formed by the pinched flap. As a result of the flow and the pressure of the lubricating oil, the flap folds out, so that the stop valve can adopt its normal function as a nonreturn valve. After the initial filling, the flap remains in its folded-out position.
Usually, motor vehicles, or their internal combustion engines, are filled or initially filled with the required operating media at the end of the production line. For this purpose, it is attempted to carry out the initial filling in a manner as efficient and time-saving as possible, that is, quickly and reliably. For example, the cooling system is evacuated for this purpose before the coolant is introduced. Nevertheless, air bubbles can remain in the system, since the thermostat is usually closed and therefore in effect forms a blockage which prevents an unimpeded flow of coolant during filling. The initial filling process is thereby extended in time. Problems also occur during a necessary refilling or topping-up process, for example during rotating, recurrent maintenance operations in workshops or the like, since these workshops possibly have not acquired an evacuation device. In particular, refilling or topping-up for maintenance purposes can have the result that the required quantity of medium is not achieved—that is, the system is filled more or less than required. This involves uncertainty factors which under certain circumstances can lead to failure of or damage to the internal combustion engine.
The inventors have herein recognized the above issues and have devised an approach to at least partially address them. Thus in one embodiment of the disclosure, a control valve for a medium circuit is provided. The control valve comprises a valve housing, an expansible material element arranged in a valve body, an energy accumulator having an abutment element, a valve seat, and at least one locking element arranged on the abutment element, each locking element having a counter-latching face. The control valve has a first position wherein the counter-latching face of each locking element is in a non-positive connection with a corresponding latching face of the valve housing in order to force the control valve into a mechanically blocked, forced-open position, the latching face being formed by means of an opening edge in the valve housing.
The control valve may be installed in the medium circuit, for example in the coolant circuit, in a completely open position by the manufacturer of the motor vehicle or of the internal combustion engine. To this end the counter-latching face of the abutment element may merely be brought into non-positive connection with the latching face of the valve housing. In this way the passages or conduits leading to the medium circuit which are to be controlled by the control valve are held open for an initial filling, so that a rapid and reliable initial filling can be made possible. Since the control valve therefore no longer blocks the coolant circuit, a preliminary evacuation of the system can also be dispensed with. In this manner, both initial filling by the manufacturer and also refilling and topping-up for maintenance purposes can be carried out quickly and reliably.